Joint Concurrent Routing and Multi-Pointer Packet Scheduling in IEEE 802.16 Mesh Networks

IEEE 802.16, also known as Worldwide Interoperability for Microwave Access (WiMAX), is a standardization effort carried out by the IEEE to provide last-mile broadband access to end users. The IEEE 802.16 standard supports two medium access control (MAC) modes - a mandatory point to multipoint (PMP) mode and an optional mesh mode. In this paper, we propose an asymmetric interference aware routing algorithm and a new multipointer approach in implementing scheduling algorithms for IEEE 802.16 mesh networks. We modify three different centralized scheduling algorithms, fixed scheduling, ordered scheduling and per-slot scheduling using multipointer approach to allow for spatial reuse (SR) in IEEE 802.16 mesh networks. Simulation results reveal that fixed scheduling with SR provides the best performance

A Survey on Scheduling in IEEE 802.16 Mesh Mode

Cataloged from PDF version of article.IEEE 802.16 standard (also known as WiMAX) defines the wireless broadband network technology which aims to solve the so called last mile problem via providing high bandwidth Internet even to the rural areas for which the cable deployment is very costly. The standard mainly focuses on the MAC and PHY layer issues, supporting two transmission modes: PMP (Point-to-Multipoint) and mesh modes. Mesh mode is an optional mode developed as an extension to PMP mode and it has the advantage of having an improving performance as more subscribers are added to the system using multi-hop routes. In 802.16 MAC protocol, mesh mode slot allocation and reservation mechanisms are left open which makes this topic a hot research area. Hence, the focus of this survey will mostly be on the mesh mode, and the proposed scheduling algorithms and performance evaluation methods

WIMAX Basics from PHY Layer to Scheduling and Multicasting Approaches

WiMAX (Worldwide Interoperability for Microwave Access) is an emerging broadband wireless technology for providing Last mile solutions for supporting higher bandwidth and multiple service classes with various quality of service requirement. The unique architecture of the WiMAX MAC and PHY layers that uses OFDMA to allocate multiple channels with different modulation schema and multiple time slots for each channel allows better adaptation of heterogeneous user’s requirements. The main architecture in WiMAX uses PMP (Point to Multipoint), Mesh mode or the new MMR (Mobile Multi hop Mode) deployments where scheduling and multicasting have different approaches. In PMP SS (Subscriber Station) connects directly to BS (Base Station) in a single hop route so channel conditions adaptations and supporting QoS for classes of services is the key points in scheduling, admission control or multicasting, while in Mesh networks SS connects to other SS Stations or to the BS in a multi hop routes, the MMR mode extends the PMP mode in which the SS connects to either a relay station (RS) or to Bs. Both MMR and Mesh uses centralized or distributed scheduling with multicasting schemas based on scheduling trees for routing. In this paper a broad study is conducted About WiMAX technology PMP and Mesh deployments from main physical layers features with differentiation of MAC layer features to scheduling and multicasting approaches in both modes of operations

Improvement of Centralized Routing and Scheduling Using Cross-Layer Design and Multi-Slot Assignment in Wimax Mesh Networks

WiMAX (Worldwide Interoperability for Microwave Access) based wireless mesh network (WMN) aims to provide broadband wireless last-mile access. It is easy to deploy, has high speed data rate for large spanning area and is the key technology for the next generation wireless networking. The WiMAX mesh network is developed with the use of base station (BS) as the main controller for all the subscriber stations (SSs). This thesis proposes an optimized strategy namely cross-layer design in routing algorithms used find the best route for all SSs and scheduling algorithms, used to assign a time slot for each possible node transmission. The cross-layer design here is relying on the routing information in network layer and the scheduling in the medium access control (MAC) layer. This thesis also proposes a centralized scheduling algorithm that can avoid the collision by constructing routing path with multi-slot single transceiver system for WiMAX mesh networks. In our proposal, each node has one transceiver that can be tuned to any of the channels in the multi-slot assignment. The design parameters such as the number of the neighboring nodes, hop count to the BS, number of children per node, slot reuse, fairness, load balancing, quality of services (QoS) and node identifier (ID) are considered. Results of analysis show that the proposed algorithms significantly improve the system performance in the aspects of length of scheduling by 30.9%, channel utilization ratio (CUR) by 50.1%, throughput of the system by 49.7%, and the end to end average transmission delay by 56.7% as compared to the MC algorithm

Adaptive load balancing routing algorithms for the next generation wireless telecommunications networks

This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel UniversityWith the rapid development of wireless networks, mesh networks are evolving as a new important technology, presenting a high research and commercial interest. Additionally, wireless mesh networks have a wide variety of applications, offering the ability to provide network access in both rural and urban areas with low cost of maintenance. One of the main functionalities of a wireless mesh network is load balancing routing, which is the procedure of finding the best, according to some criteria, routes that data need to follow to transfer from one node to another. Routing is one of the state-of-the-art areas of research because the current algorithms and protocols are not efficient and effective due to the diversity of the characteristics of these networks. In this thesis, two new routing algorithms have been developed for No Intra-Cell Interference (NICI) and Limited Intra-Cell Interference (LICI) networks based on WiMAX, the most advanced wireless technology ready for deployment. The algorithms created are based on the classical Dijkstra and Ford-Fulkerson algorithms and can be implemented in the cases of unicast and multicast transmission respectively.State scholarships foundation of Greece

An Integrated Routing and Distributed Scheduling Approach for Hybrid IEEE 802.16E Mesh Networks For Vehicular Broadband Communications

An integrated routing and distributed scheduling approach for fast deployable IEEE 802.16e networks is presented where distributed base stations with dual radios form a mesh backhaul and subscriber stations communicate through these base stations. The mesh backhaul is formed via an IEEE 802.16e mesh mode radio on each base station, while the subscriber stations communicate with base stations via PMP mode radios. The proposed routing scheme divides the deployed network into several routing zones. Each routing zone contains several base stations that form the mesh backhaul with one base station equipped with either a fiber, satellite or any other point-to-point backhaul link to reach a gateway on the core network (for example, Internet or Enterprise Network). Traffic from the subscriber stations is routed by the serving base station through the mesh to the gateway-connected base station using min-hop routing metric. Mobile IP scheme is used to assign a care-of address to a subscriber station that moves from one routing zone to the other, thereby avoiding a change in IP address for network layer applications. The scheduling approach consists of two phases. In the first phase, a centralized mesh scheduling algorithm is applied with collected information on network topology, radio parameters, and initial QoS provisioning requirements. At the same time, each base station derives a PMP schedule for actual demands from associated subscriber stations constrained by the initial mesh schedule. In the second phase, each base station monitors its carried PMP traffic load statistics; to accommodate traffic load changes in a distributed fashion, each base station lends or borrows time slots from neighboring base stations to adjust its mesh and PMP radio schedules. The distributed schedule adaptation method not only allows individual base stations to accommodate short-term increases in bandwidth demands, it also provides the means for optimizing the mesh and PMP schedules with respect to actual bandwidth demands. Several deployment strategies are considered and an analytical model is developed to identify the achievable increase in overall network throughput using the proposed scheduling approach. Simulations are run in network simulator ns-2 to verify results obtained using the analytical model